Evaluation of inflammatory response of EDTA, EDTA-T, and citric acid in animal model.

INTRODUCTION: The biocompatibility of chelating agents and organic acids have been explained by a variety of methods, and suggestions for use have been based more on clinical observations and physicochemical properties than on biological aspects. The present study aimed to evaluate the inflammatory response of 17% EDTA, 17% EDTA-T, and 10% citric acid in bony defect created in rat jaws. METHODS: Mandibular through and through critical size defects were created bilaterally in 60 rats. Fibrinol (Baldacchi SA, São Paulo, Brazil), a cube-shaped compound of absorbable bovine fibrin foam and sodium chloride, was used as a carrier of the substances. One side had received Fibrinol (control), whereas the opposite side had received Fibrinol soaked with each substance on the 1st, on the 7th, on the 14th, and on the 28th day (n=5 for each day). Hemijaws were prepared for light microscopy, and samples were stained with hematoxylin and eosin. Digitized images were analyzed with a morphometric software (ImageJ; National Institute of Mental Health, Bethesda, MD). to obtain the number of inflammatory cells per area. Comparisons were performed by using the Kruskal-Wallis test (p=0.05). RESULTS: For all days, 10% citric acid and 17% EDTA-T showed, respectively, the lowest and highest number of inflammatory cells per area. All tested substances and controls showed the highest inflammatory cell response on the 14th day. CONCLUSION: Among the tested substances, 10% citric acid proved to be the less aggressive tested solution at 14 days. At 28 days, all solutions were similar, but EDTA-T kept showing the higher number of inflammatory cells.

Proteinograma sérico de bezerros recém-nascidos da raça Holandesa obtido por eletroforese em gel de poliacrilamida / Serum protein concentration in newborn Holstein calves determined by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis

The serum protein concentration of newborn Holstein calves determined by means of sodium dodecyl sulphate-polyacrylamide (SDS-PAGE) was studied. Blood samples from 40 healthy newborn calves were obtained 48 hours after birth. Calves had been given 3 liters of colostrum within 2 hours after birth, following by dose corresponding by 15 percent of animal weight each 24 hours. The results showed three different proteinograms: 19 calves had 14 proteins with molecular weights (MW) ranging from 28,000 D to 170,000D (proteinogram 1); 11 calves had 14 proteins with MW ranging from 18,000 to 170,000 D (proteinogram 1); and 10 calves had 12 proteins with MW ranging from 28,000 D to 170,000 D (proteinogram 3). The three groups presented similar IgG levels. The highest serum concentration of ceruloplasmin were verified in proteinogram 3, which had the lowest serum level of protein with MW 58,000D. It was verified a1-antitrypsin only in proteinogram 2, which had no proteins with MW of 42,000 D and 37,000D. The highest serum concentrations of IgA and protein with MW 58,000 D, and the lowest serum levels of transferrin, haptoglobin, and acid glycoprotein were verified in proteinogram 3. Measurement of serum protein concentrations by SDS-PAGE may be useful in monitoring the occurrence of hypogammaglobulinemia and the neonatal disease in calves.(AU)

Proteinograma sérico de bezerros recém-nascidos da raça Holandesa obtido por eletroforese em gel de poliacrilamida / Serum protein concentration in newborn Holstein calves determined by means of sodium dodecyl sulphate-polyacrylamide gel electrophoresis

The serum protein concentration of newborn Holstein calves determined by means of sodium dodecyl sulphate-polyacrylamide (SDS-PAGE) was studied. Blood samples from 40 healthy newborn calves were obtained 48 hours after birth. Calves had been given 3 liters of colostrum within 2 hours after birth, following by dose corresponding by 15 percent of animal weight each 24 hours. The results showed three different proteinograms: 19 calves had 14 proteins with molecular weights (MW) ranging from 28,000 D to 170,000D (proteinogram 1); 11 calves had 14 proteins with MW ranging from 18,000 to 170,000 D (proteinogram 1); and 10 calves had 12 proteins with MW ranging from 28,000 D to 170,000 D (proteinogram 3). The three groups presented similar IgG levels. The highest serum concentration of ceruloplasmin were verified in proteinogram 3, which had the lowest serum level of protein with MW 58,000D. It was verified a1-antitrypsin only in proteinogram 2, which had no proteins with MW of 42,000 D and 37,000D. The highest serum concentrations of IgA and protein with MW 58,000 D, and the lowest serum levels of transferrin, haptoglobin, and acid glycoprotein were verified in proteinogram 3. Measurement of serum protein concentrations by SDS-PAGE may be useful in monitoring the occurrence of hypogammaglobulinemia and the neonatal disease in calves.

Effectiveness of EDTA and EDTA-T brushing on the removal of root surface smear layer.

The purpose of this study was to compare the removal of root surface smear layer following active application of EDTA gel and EDTA-T (texapon) gel in different concentrations (5%, 10%, 15%, 20% and 24%), using scanning electron microscopy. A total of 220 dentin blocks obtained from the root surfaces of extracted teeth were divided into 3 groups: Group I - (control) application of saline solution (n = 20); Group II - EDTA gel (pH 7.0) was applied in the following concentrations: 5%, 10%, 15%, 20% and 24% (n = 100); Group III - EDTA-T gel (pH 7.0) applied in the same concentrations described above (n = 100). The photomicrographs were evaluated by one calibrated examiner using a smear layer removal index and following statistical analysis (Kruskal-Wallis test). The results demonstrated that the specimens treated with EDTA and EDTA-T gel presented a better smear layer removal than the control group (p < 0.01); no statistically significant differences were observed between the EDTA and EDTA-T groups and between the concentrations tested (Mann-Whitney, p > 0.05). Within the limits of this study, it can be concluded that all treatment modalities effectively removed the smear layer from the root surface. The addition of texapon into the EDTA gel formulation did not increase its effectiveness.

Effects of sodium dodecyl sulfate on the conformation and hemolytic activity of St I and St II, two isotoxins purified from Stichodactyla helianthus.

The effect of sodium dodecyl sulfate (SDS) upon the conformation and hemolytic activity of St I and St II strongly depends on its concentration. At relatively low surfactant concentrations (ca. 0.5-5mM range) the surfactant leads to the formation of aggregates, as suggested by the turbidity observed even at relatively low (micromolar range) protein concentrations. In this surfactant range, the proteins show an increase in intrinsic fluorescence intensity and reduced quenching by acrylamide, with an almost total loss of its hemolytic activity. At higher surfactant concentrations the protein adducts disaggregates. This produces a decrease in fluorescence intensity, increase in quenching efficiency by acrylamide, loss of the native tertiary conformation (as reported by the near UV-CD spectra), and increase in alpha-helix content (as evidenced by the far UV-CD spectra). However, and in spite of these substantial changes, the toxins partially recover their hemolytic activity. The reasons for this recovering of the activity at high surfactant concentrations is discussed.

SEM study of different treatments of the smear layer on different cavity walls.

The present study evaluated the effects of slightly demineralizing treatments on dentinal cavity walls, since some recently developed adhesive procedures are applied over the smear layer. Ten experimental treatments--mechanical, chemical or mechanical/chemical--were applied on MOD cavity walls prepared in vitro with diamond burs. The dentinal surface of a lateral and of a pulpal wall of each cavity was evaluated through scanning electron microscopy, and the effects of the treatments were compared. All treatments except air/water spray removed some of the smear layer, and slight differences were observed regarding the studied cavity walls: on dentin from pulpal walls the enamel hatchet associated with tannic acid produced a better effect than the other treatments, and on dentin from lateral walls the biological detergent rubbed with cotton pellets was a little more effective than the other treatments. The effect of the smear layer treatment on dentin is different according to the wall and to the applied treatment.

Effects of subinhibitory concentrations of chemical agents on hydrophobicity and in vitro adherence of Streptococcus mutans and Streptococcus sanguis.

The aim of this investigation was to determine whether sublethal concentrations of chlorhexidine (Cx), hexetidine (Hx), cetylpyridinium chloride (Cc), sodium dodecyl sulfate (SDS), sanguinarine (Sg), sodium fluoride (NaF), and ammonium fluoride (NH4F) could affect hydrophobicity and adhesion of Streptococcus sanguis and Streptococcus mutans to saliva-coated hydroxyapatite (S-HA). Determination of the minimum inhibitory concentrations (MICs) showed that both species were susceptible to all agents tested. Growth in the presence of sub-MIC concentrations of Cx, SDS, Cc, NaF, or NH4F did not change significantly the hydrophobicity of S. sanguis cells when compared to the control which lacked any agent. However, growth in the presence of Hx or Sg resulted in a significant reduction in their hydrophobicity. Sub-MIC levels of SDS or Sg in the growth medium resulted in S. mutans cells with increased affinity for hexadecane compared with the control. The adherence of S. sanguis was changed significantly only by Hx or Sg, resulting in less cells adhering to S-HA. However, S. mutans cells previously incubated with NaF, NH4F, or Sg showed a higher adherence to S-HA than the control. The mechanisms of interference with adherence are at present not completely understood. Thus, antimicrobial agents at sub-MIC concentrations can interfere selectively with hydrophobicity and/or adhesion of oral streptococci.